Anhydrite Screeds: Are You Confident When Tiling To Them?

[Ajax123]

Well we had a good bit of news today regarding this installation,
The heating is getting turned down & switched off & there is a further moisture test taking place next week.
Hopefully they are starting to listen to me regarding this screed.

On another note the builder foned Bal technical & they told him, "contact Schluter, they have a membrane that you can put down on it".

I'm glad that you guys on here have put me in the picture as this kind of advice is not helpful.

oh good more advice to contend with.... Ditra can in theory be placed on an anhydrite screed at 2% moisture but what do you stick it down with. Schluter tend to recommend BaL which is fine but BaL adhesive is cement based and their recomendation is that the screed is primed using APD primer. APD primer is only recommended on screeds below 0.5% moisture. You could use a calcium sulphate adhesive to stick it down with but schluter wont give you a recomendation for that as they have not tested it.... Catch 22.

Stick to your guns STEF and don't stick anything down until YOU are certain of its success. If you want my advice that will be when it has been force dried, cooled, moisture tested, proven suitably dry, sanded and vacuumed

 

[Stef]

oh good more advice to contend with.... Ditra can in theory be placed on an anhydrite screed at 2% moisture but what do you stick it down with. Schluter tend to recommend BaL which is fine but BaL adhesive is cement based and their recomendation is that the screed is primed using APD primer. APD primer is only recommended on screeds below 0.5% moisture. You could use a calcium sulphate adhesive to stick it down with but schluter wont give you a recomendation for that as they have not tested it.... Catch 22.

Stick to your guns STEF and don't stick anything down until YOU are certain of its success. If you want my advice that will be when it has been force dried, cooled, moisture tested, proven suitably dry, sanded and vacuumed

Alan, thanks for that.
I'm sticking to my guns & not laying a tile till I'm happy that this instillation won't fail.
Funnily enough Bal told them about APD, I explained that I had an acrylic primer already on site, PR360 as I mostly use weber.
I've already been on the Phone to lee @ tile town about AnhyFix from tile master & explained I can go over this floor at 85 rh.
Will they listen? Only time will tell..

 

[Ajax123]

Alan, thanks for that.
I'm sticking to my guns & not laying a tile till I'm happy that this instillation won't fail.
Funnily enough Bal told them about APD, I explained that I had an acrylic primer already on site, PR360 as I mostly use weber.
I've already been on the Phone to lee @ tile town about AnhyFix from tile master & explained I can go over this floor at 85 rh.
Will they listen? Only time will tell..

What type of tiles are they stef?

 

[Stef]

In the kitchen they are
Dual core sand Matt 600x300 35m2??

& in the vestibule & hall they are
Marazzi Zenith Sahara 600x300 37m2?

Both porcelain tiles..

 

[Ajax123]

Then ditra is not needed and I would deffo go with a gypsum compatible addy.

 

[Dan]

Has any of this changed now we've had a couple more years with them?

 

[White Room]

Still never seen one let alone fixed to it....